|Year : 2022 | Volume
| Issue : 1 | Page : 159-161
Three branches involvement in retinal vein occlusion
Fatemeh Abdi1, Parya Abdolalizadeh1, Amin Zand1, Arzhang Gordiz1, Mahsa Sardarinia1, Tahmineh Motevasseli2
1 Eye Research Center, The Five Senses Institute, Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
2 Department of Ophthalmology, Shiley Eye Institute; Jacobs Retina Center, University of California San Diego, La Jolla, CA, USA
|Date of Submission||30-May-2021|
|Date of Acceptance||28-Aug-2021|
|Date of Web Publication||07-Jan-2022|
Dr. Tahmineh Motevasseli
Shiley Eye Institute, Jacob Retina Center, 9415 Campus Point Drive, #0946, La Jolla, CA 92093
Source of Support: None, Conflict of Interest: None
Two patients presented with sudden painless unilateral blurry vision. The first patient was a 57-year-old female, and the second was a 71-year-old male. The medical history of the first patient was significant for diabetes mellitus and systemic hypertension. Funduscopy of both revealed an unusual form of RVO, occlusion of three main veins of the retina, with concomitant intraretinal hemorrhages, and macular edema. An extensive ischemic retina was found in the fluorescein angiography of the second patient. Retinal vein occlusion can present as three main veins occlusion in some patients due to rare anatomic variation.
Keywords: Main retinal vein, papillary vein, retinal vein occlusion
|How to cite this article:|
Abdi F, Abdolalizadeh P, Zand A, Gordiz A, Sardarinia M, Motevasseli T. Three branches involvement in retinal vein occlusion. Indian J Ophthalmol Case Rep 2022;2:159-61
|How to cite this URL:|
Abdi F, Abdolalizadeh P, Zand A, Gordiz A, Sardarinia M, Motevasseli T. Three branches involvement in retinal vein occlusion. Indian J Ophthalmol Case Rep [serial online] 2022 [cited 2022 Aug 14];2:159-61. Available from: https://www.ijoreports.in/text.asp?2022/2/1/159/334881
Retinal vein occlusion (RVO) is the second most common retinal vascular disorder after diabetic retinopathy. Occluded retinal venous drainage is divided into branch (BRVO) and central (CRVO) retinal vein occlusions. Additionally, another entity of RVO has been identified as hemi-RVO, which involves approximately half of the retina. Hemi-RVO seems to be closely related to CRVO in terms of clinical and pathological features.
The occlusion site varies across different types of RVO. The arteriovenous crossings are the usual site of occlusion in BRVO, whereas the venous blockage occurs more proximal in CRVO involving proximal to the lamina cribrosa of the optic nerve, where the central retinal vein leaves the eye., Obstruction of one of the two main venous retinal trunk can cause hemi-RVO. Herein, we present our findings on two atypical cases of RVO involving three out of four main retinal venous branches. The informed consent was obtained from two cases.
| Case Reports|| |
Patient 1: A 57-year-old female with controlled diabetes mellitus presented with a 5-day history of painless sudden vision loss in the right eye. Her medical history was significant for hypertension controlled by anti-hypertensive medication. In her ophthalmologic examination, the best-corrected visual acuity was 20/60 in the right eye and 20/20 in the left eye. Relative afferent pupillary defect was not present in either eye, and intraocular pressures were 14 mm Hg bilaterally. Anterior segment examination of both eyes was within normal limits. At the fundus examination, the left eye was completely normal; however, examination of the right retina revealed deep and superficial intraretinal hemorrhages, venous dilation, and tortuosity in all quadrants except inferotemporal as well as normal right optic disc and macular edema [Figure 1]a. The macular optical coherence tomography (OCT) confirmed subretinal fluid, thickening of the retina, and small cystic changes within the neurosensory retina [Figure 1]b. No obvious vascular dropout in both superficial and deep capillary plexuses was found in macular OCT-angiography of the affected eye [Figure 1]c and [Figure 1]d. Investigations did not reveal any particular cardiovascular diseases. The laboratory tests for thrombophilic disorders were normal, including antithrombin III, factor V Leiden, antiphospholipid antibodies, C, and S anticoagulant proteins.
|Figure 1: (a) Right-eye color fundus: intraretinal hemorrhages and venous dilation and tortuosity in all quadrants except inferotemporal. (b) Optical coherence tomography (OCT), cystoid macular edema, subretinal fluid, and focal vitreomacular traction. (c-f) Optical coherence tomography-angiography (OCTA) (near normal): (c) superficial capillary plexus; (d) deep capillary plexus (projection of superficial capillary plexus is seen); (e) outer retina; (f) choriocapillaris|
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Patient 2: A 71-year-old man with negative past medical history was referred to the eye clinic with sudden painless reduction of vision in the right eye since two weeks before the examination, which revealed best-corrected visual acuity of hand motion in the right eye and 20/32 in the left eye. Pupil exam showed sluggish right pupil with a relative afferent papillary defect. Intraocular pressure was normal in both eyes. Fundus examination of the right eye showed a cup-to-disc ratio of 0.6 and dilated and tortuous retinal veins, with extensive superficial intraretinal hemorrhages and cotton wool spots, especially in the peripapillary region at all quadrants except the supratemporal area [Figure 2]a. The left eye exam was not contributory. Fluorescein angiography of the right eye detected extensive capillary nonperfusion area in the involved quadrants [Figure 2]b. OCT confirmed marked macular edema [Figure 2]c.
|Figure 2: (a) Right eye color fundus: optic disc cupping, dilated and tortuous retinal veins, with intraretinal hemorrhages and cotton wool spots at all quadrants except superonasal. (b) Fluorescein angiography (FA): extensive areas of capillary non-perfusion in involved quadrants. (c) Optical Coherence Tomography (OCT): Increased retinal thickness with intraretinal cysts|
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| Discussion|| |
There are three known types of RVO (CRVO, BRVO, and hemi-RVO) that are compatible with our current knowledge of retinal vein anatomy. Moreover, a review of retinal venous anatomy can be helpful to understand the pathophysiology of the RVOs. Briefly, convergence of minor retinal veins forms the main veins of retinal quadrants. The union of superotemporal and superonasal main veins in the superior hemifield makes the superior papillary vein. The inferior papillary vein is developed similarly by the merging of inferotemporal and inferonasal main veins. Two papillary veins join together at either optic nerve head or within it to make the central retinal vein. There are some clues in examination and fluorescein angiography of acute RVO that can be helpful to determine the site of occlusion, including abrupt changes of venous caliber and the distribution of retinal ischemia.
The area of arteriovenous crossing is the most common site of RVO. The Superotemporal quadrant is the most commonly affected quadrant of the retina in 63%–66% of eyes affected with BRVO. Inferotemporal quadrant involves 22%–43% of eyes with BRVO and nasal involvement is rare.
The subtypes of the RVOs according to the occlusion site differ significantly in terms of both ocular and systemic features. The area of arteriovenous crossing is the most common site of RVO usually occurring away from the optic disc. The venous compression at the crossing site by the arterial wall has been proposed as the underlying mechanism in this type of RVO. Optic nerve-sited RVOs are due to the involvement of the central retinal vein or papillary vein. Occasionally, both the superior and inferior papillary veins can be occluded in the optic cup and be mistaken for a CRVO. Absence of optic nerve swelling indicates that the site of occlusion is located at the lamina cribrosa and the proportion of CRVO and papillary vein occlusion are nearly similar., However, presence of optic nerve swelling increases the possibility of CRVO as the underlying mechanism.
Our patients had an unusual presentation not classified into the usual categories of RVOs. We hypothesize that our patients might have a rare anatomical variation whose one papillary vein was formed by the union of three retinal main veins rather than two. Consequently, the occlusion of the three-branch papillary vein led to the involvement of the three main retinal veins and their territories in retinal tissues. However, by considering the typical anatomy of the retinal venous network, simultaneous multilevel occlusion including one main retinal vein and one papillary vein might occur in our cases. This atypical subtype of RVO can be presented as either ischemic (case 2) or nonischemic (case 1).
| Conclusion|| |
The present study is a report of the three vessels' involvement in RVO. Based on these cases, RVO patients could be different from the present RVO classification. Additionally, appropriate imaging tools are required to investigate the venous network and their branching in vivo, especially the parts that are obscured behind the lamina cribrosa.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]